clii Report of the Mineralogical Survey [No. 126*. 



or irregularities occur to embarrass us ; none of the transitions or 

 mixtures which are found in nature, and which form the difficulties of 

 the pursuit, " La on trouve tout dispose selon le systeme." The same 

 may be said of our most approved geological systems. There we find 

 every rock occupying its distinct quarter, and no hint of the great and 

 perplexing irregularities with which the sjtudent of nature has to struggle 

 at every step. We have granite occupying the lowest and the highest 

 points, a covering of gneiss resting on the granite excepting at the 

 very highest points, mica slate over the gneiss, clay slate over it again, 

 and so on in regular array, and with the outgoings of the newer 

 and newer strata. At lower and lower levels, such an account of 

 things is no doubt very beautiful, very systematic, and indeed has 

 but one fault, that it is not true. As countries have been examined 

 more particularly, it is found, that excepting in a few grand points, 

 not one country will serve for an exact type of another. 



327. We have seen that in these mountains,* gneiss occupies the 

 greatest part of the surface. Its thickness is considerable, if we adopt 

 the commonly received opinions of stratification.f To this succeed 

 various schists, the true relations and connections of which are very 

 obscure ; micaceous, talcose, chloritic and argillaceous in different places 

 are conterminous with the gneiss. In the schists and in the zone 

 of least elevation, we find a series of patches of granite disposed 

 along a line parallel to that of the direction of the mountain band 

 and strata. Beyond these again, we see an extensive zone of clay 

 slate, in which occasional patches of gneiss also are found, and 

 outside of the whole very limited examples of the secondary strata, 

 which are finally lost in the plains. 



328. Here then is a very different arrangement from that just 



* Professor Jameson in one of his latest works mentions the Himmalaya as an 

 example of a granitic chain. It would be interesting to know on what authority 

 he founds his opinion. I have seen more of these mountains than any European, and 

 the only granite within the above tract (beyond which we cannot without great 

 violence apply the term Himmalaya) that I have ever seen consists of fragments in 

 the beds of rivers. I have never had any doubts, and if 1 had, the occurrence of these 

 fragments would remove them; but that there are occasionally veins and perhaps 

 larger patches of granite as in other parts of these mountains, but I have never within 

 this tract met with any rock, in situ, but gneiss and its contained beds. 



f There are, however, some good reasons for rejecting this indefinite continuity of 

 the strata underneath, at least in the direction in which they appear on the surface. 



